They believe Japan did nothing wrong during their militarist regime before 1945. I'm pretty sure most Japs believe that they never did anything wrong, not just the militarists.
Japs are quite skilled at pretending nothing is or was wrong. For example: Issei Sagawa.
To them, Japanese are the most peace-loving sensitive souls. After the war, all they bothered to remember about it was the two nuclear bombs dropped on their soil. They view themselves as victims of unimaginable atrocity. Of course, they can't openly point finger at U.S.. However, it is an strong undercurrent. It is a typical exercise of selective memory. For more than three decades, peace movement swept the entire country, not because of reflecting on destruction they wrought, but their "victimization" by two bombs.
Japan was an aggressor nation, which was reborn as a victim nation after the war.